The present invention relates to a semiconductor device manufacturing technique and more particularly to a technique applicable effectively to a semiconductor device wherein a semiconductor chip having salient electrodes is facedown-mounted to a flexible-film substrate.
In association with semiconductor devices wherein a semiconductor chip having salient electrodes such as Au bumps is facedown-mounted to a flexible film substrate there are known TAB (Tape Automated Bonding) and TCP (Tape Carrier Package).
The flexible substrate used in the aforesaid TAB or TCP generally comprises an insulating film formed by a polyimide resin for example and plural Cu leads formed on the surface of the insulating film. Therefore, it is known that there occur expansion and contraction of the insulating film due to moisture contained in the atmosphere and that an error of lead pitch results.
For example, in Japanese Published Unexamined Patent Application No. 2001-144144 it is pointed out that maintaining the humidity at 60% or so is important for preventing a change in lead pitch caused by expansion or contraction of an insulating film which is attributable to a change in humidity.
Japanese Published Unexamined Patent Application No. 2000-124255 discloses a technique of narrowing the lead pitch beforehand by the amount of an increase in lead pitch caused by expansion of an insulating film as a measure against the occurrence of an error in lead pitch which error results from expansion of the insulating film in the presence of moisture or heat contained in the atmosphere.